Method and system of reducing block boundary artifacts in digital image processing

ABSTRACT

In one aspect, in one aspect, a computerized method useful for reducing block boundary artifacts in a digital image processing that includes the step of obtaining an original digital image to scrambled. The method includes the step of generating a uniform grid of boxes in the digital image. At a boundary of each box in the uniform grid of boxes, a frame for each box is generated by replicating each of a set of boundary pixels a specified number of times to generate a thicker boundary. The method incudes the step of scrambling the uniform grid of boxes of the digital image.

This application claims priority to U.S. application Ser. No. 15/787,692filed on 18 Oct. 2017 and titled METHOD AND SYSTEM OF REDUCING BLOCKBOUNDARY ARTIFACTS IN DIGITAL IMAGE PROCESSING. U.S. application Ser.No. 15/787,692 claims priority to U.S. Provisional Application No.62/409,852 filed on Oct. 18, 2016 and titled METHOD AND SYSTEM OFREDUCING BLOCK BOUNDARY ARTIFACTS IN DIGITAL IMAGE PROCESSING. Theseapplications are incorporated by reference in their entirety.

BACKGROUND 1. Field

This application relates to digital image processing and morespecifically to a system, article of manufacture and method for reducingblock boundary artifacts in digital image processing.

2. Related Art

A digital image can be scrambled. The scrambled image can then befurther manipulated (e.g. encoded, compressed, etc.). When the image islater descrambled, block artifacts can have been introduced to theimage. FIG. 1 illustrates an example of a digital image with blockartifacts. If image wasn't scrambled, this information that may be lostin a correct order and the grid effect of the block artifacts may not bepresent.

SUMMARY

In one aspect, a computerized method useful for reducing block boundaryartifacts in a digital image processing that includes the step ofobtaining an original digital image to scrambled. The method includesthe step of generating a uniform grid of boxes in the digital image. Ata boundary of each box in the uniform grid of boxes, a frame for eachbox is generated by replicating each of a set of boundary pixels aspecified number of times to generate a thicker boundary. The methodincudes the step of scrambling the uniform grid of boxes of the digitalimage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a digital image with block artifacts,according to some embodiments.

FIG. 2 illustrates an example method for reducing block boundaryartifacts when encoding a digital image, according to some embodiments.

FIG. 3 illustrates an example process for descrambling a digital imagescramble using process, according to some embodiments.

FIG. 4 illustrates an example pair of copies of a single image to bescrambled, according to some embodiments.

FIG. 5 a process of scrambling a digital image, according to someembodiments.

FIG. 6 depicts an exemplary computing system that can be configured toperform any one of the processes provided herein.

FIG. 7 is a block diagram of a sample computing environment that can beutilized to implement various embodiments.

The Figures described above are a representative set, and are not anexhaustive with respect to embodying the invention.

DESCRIPTION

Disclosed are a system, method, and article of manufacture for methodsand systems for reducing block boundary artifacts in digital imageprocessing. The following description is presented to enable a person ofordinary skill in the art to make and use the various embodiments.Descriptions of specific devices, techniques, and applications areprovided only as examples. Various modifications to the examplesdescribed herein can be readily apparent to those of ordinary skill inthe art, and the general principles defined herein may be applied toother examples and applications without departing from the spirit andscope of the various embodiments.

Reference throughout this specification to ‘one embodiment;’ ‘anembodiment,’ ‘one example,’ or similar language means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the presentinvention. Thus, appearances of the phrases ‘in one embodiment,’ ‘in anembodiment,’ and similar language throughout this specification may, butdo not necessarily, all refer to the same embodiment.

Furthermore, the described features, structures, or characteristics ofthe invention may be combined in any suitable manner in one or moreembodiments. In the following description, numerous specific details areprovided, such as examples of programming, software modules, userselections, network transactions, database queries, database structures,hardware modules, hardware circuits, hardware chips, etc., to provide athorough understanding of embodiments of the invention. One skilled inthe relevant art can recognize, however, that the invention may bepracticed without one or more of the specific details, or with othermethods, components, materials, and so forth. In other instances,well-known structures, materials, or operations are not shown ordescribed in detail to avoid obscuring aspects of the invention.

The schematic flow chart diagrams included herein are generally setforth as logical flow chart diagrams. As such, the depicted order andlabeled steps are indicative of one embodiment of the presented method.Other steps and methods may be conceived that are equivalent infunction, logic, or effect to one or more steps, or portions thereof, ofthe illustrated method. Additionally, the format and symbols employedare provided to explain the logical steps of the method and areunderstood not to limit the scope of the method. Although various arrowtypes and line types may be employed in the flow chart diagrams, andthey are understood not to limit the scope of the corresponding method.Indeed, some arrows or other connectors may be used to indicate only thelogical flow of the method. For instance, an arrow may indicate awaiting or monitoring period of unspecified duration between enumeratedsteps of the depicted method. Additionally, the order in which aparticular method occurs may or may not strictly adhere to the order ofthe corresponding steps shown.

Example Definitions

Channel can be a grayscale image of the same size as a color image, butmade of just one primary color. For instance, an image from a standarddigital camera will have a red, green and blue channel.

Compression artifact is a noticeable distortion of media caused by theapplication of lossy data compression.

A box (e.g. a pixel box) can be a set of n×n pixels of a digital image.Boxes can be scrambled and/or otherwise reordered to encode the digitalimage.

Example Methods

In one example embodiment, a digital image can be scrambled and/orotherwise encoded before it becomes publicly accessible. The digitalimage can be doubled to create two copies. A first copy of the digitalimage can be divided into a grid of uniform boxes of a specified pixelsize. This grid can then be offset (e.g. by half the box size of thefirst copy of the digital image, etc.) for the second copy of thedigital image. The boxes can then be used as units for scrambling thetwo copies of the digital together.

When the scrambled digital image is descrambled, a boundary artifact canbe detected in the grid boundaries of the first copy of the digitalimage. The boundary artifact can be the result of a loss of informationat the boundaries of the boxes during a lossy compression and/or otherdigital image manipulation processes that occurs while the digital imageis in a scrambled state. The boundary artifact can be reduced bysampling the middle/center rows and/or columns of the boxes of theoffset grid of the second copy of the digital image. These non-boundarycenter rows and/or columns can then be substituted for the gridboundaries of the first copy. In this way, given a box size of ten byten (10×10) pixels, a border error of forty (40) pixels can be reducedto four (pixels), for example.

FIG. 2 illustrates an example method 200 for reducing block boundaryartifacts when encoding a digital image, according to some embodiments.In step 202, process 200 can obtain a digital image. In step 204,process 200 can create a copy the digital image. In step 206, process200 can delineate a first pixel-box grid on the digital image. A pixelbox can be a unit of the digital image to be reordered/scrambled. A boxsize can be measured by the number of pixels in each boundary. Forexample, a box can be five by five pixels, ten by ten pixels, etc. Step206 can begin box delineation at a specified set of coordinates (e.g.(0, 0)) and then, depending on the box size, step 206 delineate theremainder of the box.

In step 208, process 200 can delineate a second pixel-box grid on thecopied digital image. The second pixel-box grid coordinates can aspecified offset of the first pixel-box grid's coordinates. For example,the specified coordinates for the first image begin at coordinate (0, 0)and the box size is ten by ten (10×10) pixels. The offset for the secondbox can be offset half the length of the boundary of the first image'sboxes. For example, the delineation of the copied images boxes can be atcoordinate (5, 5) and the box size can be ten by ten (10×10) pixels. Insome example embodiments, the first copy image can then be placed in asingle double digital image with the second copy image.

In step 210, process 100 join the original digital image and the copy ofthe digital image. The boxes of the two digital images can be offset. Instep 212, process 200 can scrabble and/or otherwise reorder the boxes ofthe image and the copy of the image into an encoded image the twodigital images. For example, the boxes of the two digital images can bescrambled together into a single scrambled and/or otherwise encodeddigital images.

FIG. 3 illustrates an example process 300 for descrambling a digitalimage scramble using process 200, according to some embodiments. In step302, process 300 can obtain a scrambled digital image. In step 304,process 300 can descramble the scramble digital image into two copies.In step 306, process 300 can detect boundary artifacts in a first copyof the digital image. For example, the grid of FIG. 1 can be apparent inthe descrambled digital image. In step 308, process 300 can sample thecenter rows and/or columns of the box grid of the second copy of thedigital image. For example, process 300 can use a line of pixels of thecenter of a corresponding box of the second image as a correspondingborder of first image. This is become the information that is lost asborders in the first copy of the image is not a border but rather acenter of the second copy of the image due to the offset of formattingthe boxes of the second copy. In step 310, process 300 can replace theboundaries of the first copy with the sampled-center rows and/or columnsthe second copy. It is noted that noise reduction and/or otheralgorithms can be implemented to further reduce the remaining distortionin the descrambled image (e.g. the four corner pixels of the boundary ofline, etc.). Using processes 200-300, an original image can be reducedin size, scrambled and then descramble and brought back to original sizewith less error.

FIG. 4 illustrates an example pair of copies 400 of a single image to bescrambled, according to some embodiments. Area 402 is a grid of a firstcopy of the digital image. Area 404 is an offset grid of second copy ofdigital image. The boxes of both copies can be scrambled together into asingle encoded image. In some examples, the partial border boxes of thesecond copy can be combined together such that all the boxes are ofequal size before a scrambling process.

FIG. 5 a process 500 of scrambling a digital image, according to someembodiments. In step 502, process 500 can obtain a digital image. Instep 504, process 500 can generate a uniform grid of boxes in thedigital image. In step 506, process 500 can, at the boundary of each boxin the grid, replicate the boundary pixels a specified number of timesto generate a thicker boundary. In step 508, process 500 can scrambleboxes of digital image. It is noted that the frame of a box can be aduplication of pixels of the border of the box. For example, the borderof the box can be one-pixel of thickness. The frame can be the one-pixelof thickness copied to a four (or other number) pixel-depth ofthickness. This can provide a ‘safety’ frame that may withstand thelater distortions (e.g. compression, resizing, encoding, etc.) of theimage. If when the digital image is later descrambled and the boundaryartifact is detected, then the other processes can be utilized to removethe boundary artifacts.

It is noted that scrambling can be a process of randomly mixing up asampled-set of pixel boxes. In some example embodiments, the pixel boxescan be non-randomly sorted using a set order as determined by variousattributes of the original digital image. For example, instead of arandom selection (e.g. as determined by a pseudo-random numbergeneration process, etc.) an ordered selection of pixel-boxes sorted canbe based on taking an average value of each channel and then resort onthree (3) planes (e.g. luminance, chrominance, etc.)

Exemplary Computer Architecture and Systems

FIG. 6 depicts an exemplary computing system 600 that can be configuredto perform any one of the processes provided herein. In this context,computing system 600 may include, for example, a processor, memory,storage, and I/O devices (e.g., monitor, keyboard, disk drive, Internetconnection, etc.). However, computing system 600 may include circuitryor other specialized hardware for carrying out some or all aspects ofthe processes. In some operational settings, computing system 600 may beconfigured as a system that includes one or more units, each of which isconfigured to carry out some aspects of the processes either insoftware, hardware, or some combination thereof.

FIG. 6 depicts computing system 600 with a number of components that maybe used to perform any of the processes described herein. The mainsystem 602 includes a motherboard 604 having an I/O section 606, one ormore central processing units (CPU) 608, and a memory section 610, whichmay have a flash memory card 612 related to it. The I/O section 606 canbe connected to a display 614, a keyboard and/or other user input (notshown), a disk storage unit 616, and a media drive unit 618. The mediadrive unit 618 can read/write a computer-readable medium 620, which cancontain programs 622 and/or data. Computing system 600 can include a webbrowser. Moreover, it is noted that computing system 600 can beconfigured to include additional systems in order to fulfill variousfunctionalities. Computing system 600 can communicate with othercomputing devices based on various computer communication protocols sucha Wi-Fi, Bluetooth® (and/or other standards for exchanging data overshort distances includes those using short-wavelength radiotransmissions), USB, Ethernet, cellular, an ultrasonic local areacommunication protocol, etc.

FIG. 7 is a block diagram of a sample computing environment 700 that canbe utilized to implement various embodiments. The system 700 furtherillustrates a system that includes one or more client(s) 702. Theclient(s) 702 can be hardware and/or software (e.g., threads, processes,computing devices). The system 700 also includes one or more server(s)704. The server(s) 704 can also be hardware and/or software (e.g.,threads, processes, computing devices). One possible communicationbetween a client 702 and a server 704 may be in the form of a datapacket adapted to be transmitted between two or more computer processes.The system 700 includes a communication framework 710 that can beemployed to facilitate communications between the client(s) 702 and theserver(s) 704. The client(s) 702 are connected to one or more clientdata store(s) 706 that can be employed to store information local to theclient(s) 702. Similarly, the server(s) 704 are connected to one or moreserver data store(s) 708 that can be employed to store information localto the server(s) 704. In some embodiments, system 700 can instead be acollection of remote computing services constituting a cloud-computingplatform.

Conclusion

Although the present embodiments have been described with reference tospecific example embodiments, various modifications and changes can bemade to these embodiments without departing from the broader spirit andscope of the various embodiments. For example, the various devices,modules, etc. described herein can be enabled and operated usinghardware circuitry, firmware, software or any combination of hardware,firmware, and software (e.g., embodied in a machine-readable medium).

In addition, it can be appreciated that the various operations,processes, and methods disclosed herein can be embodied in amachine-readable medium and/or a machine accessible medium compatiblewith a data processing system (e.g., a computer system), and can beperformed in any order (e.g., including using means for achieving thevarious operations). Accordingly, the specification and drawings are tobe regarded in an illustrative rather than a restrictive sense. In someembodiments, the machine-readable medium can be a non-transitory form ofmachine-readable medium.

What is claimed as new and desired to be protected by Letters Patent of the United States is:
 1. A computerized method useful for reducing block boundary artifacts in a digital image processing comprising: obtaining an original digital image to scrambled; generating a uniform grid of boxes in the digital image; at a boundary of each box in the uniform grid of boxes, generating a frame for each box by replicating each of a set of boundary pixels a specified number of times to generate a thicker boundary; and scrambling the uniform grid of boxes of the digital image.
 2. The computerized method of claim 1, wherein the frame of each box comprises a duplication of a set of pixels of the border of the box.
 3. The computerized method of claim 2, wherein the frame of the box comprises a one-pixel of thickness.
 4. The computerized method of claim 2, wherein the frame comprises the one-pixel of thickness copied to a greater than one specified pixel-depth of thickness.
 5. The computerized method of claim 4, wherein the frame comprises the one-pixel of thickness copied to a four pixel-depth of thickness.
 6. The computerized method of claim 2 further comprising: descrambling the scramble image.
 7. The computerized method of claim 6 further comprising: detecting the boundary artifact in the descrambled image.
 8. The computerized method of claim 7 further comprising: removing the boundary artifact.
 9. The computerized method of claim 1 further comprising: implementing an image compression algorithm on the scrambled image.
 10. The computerized method of claim 1, wherein a box of the uniform grid of boxes comprises a rectangular pixel box of a set of n×n pixels of the digital image.
 11. The computerized method of claim 1, wherein the box comprises a rectangular pixel box of a set of n×m pixels of the digital image.
 12. A computerized system useful for reducing block boundary artifacts in digital image processing comprising: a processor; a memory containing instructions when executed on the processor, causes the processor to perform operations that: obtain an original digital image to scrambled; generate a uniform grid of boxes in the digital image; at a boundary of each box in the uniform grid of boxes, generate a frame for each box by replicating each of a set of boundary pixels a specified number of times to generate a thicker boundary; and scramble the uniform grid of boxes of the digital image.
 13. The computerized system of claim 12, wherein the frame of each box comprises duplication of a set of pixels of the border of the box.
 14. The computerized system of claim 13, wherein the frame of the box comprises a one-pixel of thickness.
 15. The computerized system of claim 13, wherein the frame comprises the one-pixel of thickness copied to a greater than one specified pixel-depth of thickness.
 16. The computerized system of claim 15, wherein the frame comprises the one-pixel of thickness copied to a four pixel-depth of thickness.
 17. The computerized system of claim 12, wherein a box of the uniform grid of boxes comprises a rectangular pixel box of a set of n×n pixels of the digital image.
 18. The computerized system of claim 12, wherein the box comprises a rectangular pixel box of a set of n×m pixels of the digital image. 